Abstract: Disclosed is an optical communication line monitoring apparatus comprising: an optical transceiver for transmitting management frames to remote devices connected to optical communication lines and receiving response frames transmitted from the remote devices; an optical time domain reflectometer (OTDR) for transmitting optical pulse signals to the optical communication lines and detecting reflection signals reflected from the optical communication lines, which have received the optical pulse signals; an optical switch for switching the optical transceiver and the OTDR at an input terminal thereof and switching each of multiple optical communication lines at an output terminal thereof; and a monitoring unit for determining whether or not a first optical communication line is abnormal based on a response frame transmitted from a first remote device, with the input terminal connected to the optical transceiver and the output terminal connected to the first optical communication line among the multiple optical co

Abstract: An ethernet-based communication system is provided. The communication system comprises: a first unit configured to generate a reference clock signal by using an input first ethernet signal, multiplex the first ethernet signal and a second ethernet signal in response to the reference clock signal, and output the multiplexed ethernet signals; a second unit configured to generate the reference clock signal by using the multiplexed ethernet signals, separate the second ethernet signal from the multiplexed ethernet signals in response to the reference clock signal, and output the first ethernet signal; and a transmission medium for connecting the first and second units and transmitting the multiplexed ethernet signals from the first unit to the second unit.

Abstract: Provided are a gravity search adaptive apparatus and method. The gravity search adaptive apparatus includes: a system configured to process and output a received signal; a system modeling unit configured to receive the same signal as a signal input to the system, to convert the signal using a system modeling parameter, and to output the converted signal; and an adaptive controller configured to use a gravity search adaptive algorithm to detect the system modeling parameter so that an error signal which is a difference between an output signal of the system and an output signal of the system modeling unit converges on a minimum value when the system modeling parameter is applied to the system modeling unit.

Abstract: In a symbol mapping apparatus, a channel coder outputs a codeword including a plurality of information bits and a plurality of redundancy bits by encoding transmission data. A symbol mapper maps the codeword to the symbol while changing a mapping scheme in the unit of the codeword.

Abstract: In a symbol mapping method, transmission data is encoded to output information bits and redundancy bits. The information bits and the redundancy bits are mapped to a symbol according to a first mapping scheme at a first transmission, and the information bits and the redundancy bits are mapped to a symbol according to a second mapping scheme at a second transmission.

Abstract: A retransmission method maps at least some bits of codeword to symbols according to a first modulation method at the time of first transmission. The retransmission method maps at least some bits of the codeword to symbols according to a second modulation method that is different from the first modulation method at the time of second transmission after the first transmission. In this case, the second modulation method may have a lower modulation order than that of the first modulation method, or a sum of average reliability per bit of symbol according to the second modulation may be larger than a sum of average reliability per bit of symbol according to the first modulation method.

Abstract: In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped.

Abstract: Provided are a gravity search adaptive apparatus and method. The gravity search adaptive apparatus includes: a system configured to process and output a received signal; a system modeling unit configured to receive the same signal as a signal input to the system, to convert the signal using a system modeling parameter, and to output the converted signal; and an adaptive controller configured to use a gravity search adaptive algorithm to detect the system modeling parameter so that an error signal which is a difference between an output signal of the system and an output signal of the system modeling unit converges on a minimum value when the system modeling parameter is applied to the system modeling unit.

Abstract: Disclosed is a bi-directional sliding-type portable terminal. The bi-directional sliding-type portable terminal comprises a phone body and a bi-directional sliding body. The phone body comprises a first section which is located on one side of the top surface thereof and within which a plurality of keys are mounted, and a second section which is located on the other side of the top surface thereof spaced apart from the first section and within which a camera lens housing is mounted. The bi-directional sliding body linearly moves on the phone body in a longitudinal direction while facing the phone body, opens the first section to expose the keys by moving toward the second section, and opens the second section to expose the camera lens housing by moving toward the first section.

Abstract: A retransmission method maps at least some bits of codeword to symbols according to a first modulation method at the time of first transmission. The retransmission method maps at least some bits of the codeword to symbols according to a second modulation method that is different from the first modulation method at the time of second transmission after the first transmission. In this case, the second modulation method may have a lower modulation order than that of the first modulation method, or a sum of average reliability per bit of symbol according to the second modulation may be larger than a sum of average reliability per bit of symbol according to the first modulation method.

Abstract: In a symbol mapping apparatus, a channel coder outputs a codeword including a plurality of information bits and a plurality of redundancy bits by encoding transmission data. A symbol mapper maps the codeword to the symbol while changing a mapping scheme in the unit of the codeword.

Abstract: In a symbol mapping method, transmission data is encoded to output information bits and redundancy bits. The information bits and the redundancy bits are mapped to a symbol according to a first mapping scheme at a first transmission, and the information bits and the redundancy bits are mapped to a symbol according to a second mapping scheme at a second transmission.

Abstract: In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped.